Magnetic materials, and methods of formation

Abstract

In a soft magnetic material, multiple flake-shaped magnetic particles: are coated by respective magnetic insulators; contain respective groups of magnetic nanoparticles; and are compacted to achieve magnetic exchange coupling between adjacent flake-shaped magnetic particles, and between adjacent magnetic nanoparticles within at least one of the flake-shaped magnetic particles.

1 . A soft magnetic material comprising:
 a plurality of flake-shaped magnetic particles that: are coated by respective magnetic insulators; contain respective groups of magnetic nanoparticles; and are compacted to achieve magnetic exchange coupling between adjacent flake-shaped magnetic particles, and between adjacent magnetic nanoparticles within at least one of the flake-shaped magnetic particles.   
     
     
         2 . The soft magnetic material of  claim 1 , wherein the magnetic nanoparticles include single domain nanoparticles. 
     
     
         3 . The soft magnetic material of  claim 2 , wherein the soft magnetic material is formed with at least one alloy that is selected to achieve the single domain nanoparticles. 
     
     
         4 . The soft magnetic material of  claim 3 , wherein the alloy is selected to increase a domain wall thickness of the soft magnetic material. 
     
     
         5 . The soft magnetic material of  claim 1 , wherein the magnetic insulators include a Ferrite. 
     
     
         6 . The soft magnetic material of  claim 1 , wherein the magnetic insulators include at least one of the following: Gamma Fe 2 O 3 ; and other Ferrites. 
     
     
         7 . The soft magnetic material of  claim 1 , wherein a thickness of the magnetic insulators is sized to achieve the magnetic exchange coupling between adjacent flake-shaped magnetic particles. 
     
     
         8 . The method of  claim 1 , wherein the compacting comprises:
 compacting the flake-shaped magnetic particles by a fast compaction process at high pressure and low temperature.   
     
     
         9 . The soft magnetic material of  claim 1 , wherein the flake-shaped magnetic particles are compacted by a combustion driven compaction process. 
     
     
         10 . The soft magnetic material of  claim 1 , wherein the compacted flake-shaped magnetic particles are annealed to relieve stresses therein. 
     
     
         11 . The soft magnetic material of  claim 1 , wherein the soft magnetic material is formed with at least one alloy that is selected to achieve the magnetic exchange coupling between adjacent flake-shaped magnetic particles, and between adjacent magnetic nanoparticles within at least one of the flake-shaped magnetic particles. 
     
     
         12 . The soft magnetic material of  claim 11 , wherein the alloy is selected to increase an exchange length of the soft magnetic material. 
     
     
         13 . The soft magnetic material of  claim 1 , wherein the flake-shaped magnetic particles are formed by milling an amorphous tape that contains the magnetic nanoparticles. 
     
     
         14 . The soft magnetic material of  claim 13 , wherein the flake-shaped magnetic particles are formed by milling the amorphous tape, without exposing the amorphous tape to an atmosphere. 
     
     
         15 . The soft magnetic material of  claim 13 , wherein the flake-shaped magnetic particles are formed by grinding the amorphous tape. 
     
     
         16 . The soft magnetic material of  claim 13 , wherein the flake-shaped magnetic particles are formed by microforging the amorphous tape. 
     
     
         17 . The soft magnetic material of  claim 1 , wherein the flake-shaped magnetic particles are formed to have high aspect (lateral dimension/thickness) ratios. 
     
     
         18 . A method of making soft magnetic material, the method comprising:
 forming a plurality of flake-shaped magnetic particles that contain respective groups of magnetic nanoparticles;   coating the flake-shaped magnetic particles with respective magnetic insulators; and   compacting the flake-shaped magnetic particles to achieve magnetic exchange coupling between adjacent flake-shaped magnetic particles, and between adjacent magnetic nanoparticles within at least one of the flake-shaped magnetic particles.   
     
     
         19 . The method of  claim 18 , wherein the forming comprises:
 forming the flake-shaped magnetic particles that contain respective groups of magnetic nanoparticles including single domain nanoparticles.   
     
     
         20 . The method of  claim 19 , wherein the forming comprises:
 forming the flake-shaped magnetic particles with at least one alloy that is selected to achieve the single domain nanoparticles.   
     
     
         21 . The method of  claim 20 , wherein the forming comprises:
 forming the flake-shaped magnetic particles with at least one alloy that is selected to increase a domain wall thickness of the soft magnetic material.   
     
     
         22 . The method of  claim 18 , wherein the coating comprises:
 coating the flake-shaped magnetic particles with respective magnetic insulators that include a Ferrite.   
     
     
         23 . The method of  claim 18 , wherein the coating comprises:
 coating the flake-shaped magnetic particles with respective magnetic insulators that include at least one of the following: Gamma Fe 2 O 3 ; and other Ferrites.   
     
     
         24 . The method of  claim 18 , wherein the coating comprises:
 coating the flake-shaped magnetic particles with respective magnetic insulators whose thickness is sized to achieve the magnetic exchange coupling between adjacent flake-shaped magnetic particles.   
     
     
         25 . The method of  claim 18 , wherein the compacting comprises:
 compacting the flake-shaped magnetic particles by a fast compaction process at high pressure and low temperature.   
     
     
         26 . The method of  claim 18 , wherein the compacting comprises:
 compacting the flake-shaped magnetic particles by a combustion driven compaction process.   
     
     
         27 . The method of  claim 18 , and comprising:
 annealing the compacted flake-shaped magnetic particles to relieve stresses therein.   
     
     
         28 . The method of  claim 18 , wherein the forming comprises:
 forming the flake-shaped magnetic particles with at least one alloy that is selected to achieve the magnetic exchange coupling between adjacent flake-shaped magnetic particles, and between adjacent magnetic nanoparticles within at least one of the flake-shaped magnetic particles.   
     
     
         29 . The method of  claim 28 , wherein the forming comprises:
 forming the flake-shaped magnetic particles with at least one alloy that is selected to increase an exchange length of the soft magnetic material.   
     
     
         30 . The method of  claim 18 , wherein the forming comprises:
 forming the flake-shaped magnetic particles by milling an amorphous tape that contains the magnetic nanoparticles.   
     
     
         31 . The method of  claim 30 , wherein the milling comprises:
 forming the flake-shaped magnetic particles by milling the amorphous tape, without exposing the amorphous tape to an atmosphere.   
     
     
         32 . The method of  claim 30 , wherein the milling comprises:
 forming the flake-shaped magnetic particles by grinding the amorphous tape.   
     
     
         33 . The method of  claim 30 , wherein the milling comprises: forming the flake-shaped magnetic particles by microforging the amorphous tape. 
     
     
         34 . The soft magnetic material of  claim 18 , wherein the flake-shaped magnetic particles are formed to have high aspect (lateral dimension/thickness) ratios.